SMART: A rapid layer adaptation protocol for layered video multicast
Jiwoong Lee, Jae‐Kyoon Kim · European Transactions on Telecommunications · 2001
Abstract This paper presents a new network layer traffic control protocol for rapid layer adaptation and prompt congestion recovery of a layered—video multicast session. The proposed protocol SMART, which stands for Scalable Multimedia Rapid Rate Control in Multicast Networks, defines a concept of dependency between multicast group addresses that are pertaining to the same layered—video session. The information on dependency is carried on an extended version of Internet Group Managenemt Protocol, which is called IGMP—DX (Dependency Extension). SMART router creates a database to manage the dependency information. With SMART, receivers can adapt their subscription level to the right level rapidly by the function of Fast Learning. Emergency Drop Request is sent by a host who detects intensive congestion, and the router blocks the associated traffic. In this manner network can recover from congestion rapidly while not impairing the minimal multicast service. SMART supports both IGMPv2 and IGMPv3, including sourcespecific multicast in Internet. It is shown by simulations that SMART provides a rapid rate control mechanism and good scalability with small amount of control signal.